1. Field of the Invention
The present invention relates to a method of manufacturing a light emitting device and a light emitting device.
2. Background Information
There has been used a surface mount type light emitting device, in which a light emitting element such as a light emitting diode (LED) or a laser diode (LD) is mounted on a substrate. Such light emitting devices are used for lighting apparatus, backlight of display screen, light source for vehicle, light source for display, auxiliary light source for moving images, and other general consumer light sources. As compared with conventional light sources, such light emitting devices have a longer life and are capable of emitting light under an energy-serving environment, which are attracting high expectation as a next generation light source for lighting applications.
In recent years, even higher levels of output powder is in demand, and in order to comply, increase in size (a larger planar dimension) of a light emitting element or a combination of plurality of small-size light emitting elements has been conducted. On the other hand, in order to produce an application product in which the orientation characteristic is controlled by using a lens system or the like, the light emitting device preferably has a light source as close to a configuration of a single light source as possible, that is, as close to a configuration of a point light source as possible. For this reason, in order to realize high power output, a use of a single, large-size light emitting element is preferable. However, although a technique of mounting a large planar dimension light emitting element on a package or the like is relatively easy to perform, production of such a light emitting element having a large planar dimension from a wafer with good yield is difficult.
For this reason, when a plurality of small sized light emitting elements, which are easily obtained with good production yield, is used, cost advantage can be attained. However, an arrangement of the plurality of light emitting elements close together in order to achieve a configuration close to a point light source is difficult to obtain due to the accuracy of mounting positions. For this reason, there has been proposed to print a solder with a pre-determined amount of offset or shift for each of the electronic components such as a plurality of light emitting elements to be mounted (for example, see JP 2002-134892A).
It is described that, with the use of self-alignment effect, this method allows positioning of each light emitting element at an intended position in the step of solder-bonding.
However, in practice with the method described in JP 2002-134892 A, the degree of accuracy of mounting positions may become unstable and a satisfactory level has not been achieved.